EPA has released the latest version of tool that estimates health risks from breathing air toxics in the United States. The National Air Toxics Assessment (NATA), based on 2002 air emissions data, helps federal, state, local and tribal governments identify areas and specific pollutants for further evaluation to better understand risks they may pose.
The 2002 NATA estimates that most people in the United States have an average cancer risk of 36 in 1 million if exposed to 2002 emissions levels over the course of their lifetime. In addition, 2 million people—less than one percent of the total U.S. population—have an increased cancer risk of greater than 100 in 1 million. Benzene was the largest contributor to the increased cancer risks.
EPA generally deems a lifetime cancer risk greater than one in 1 million to be unacceptable.
Information on air toxics:  www.epa.gov/oar/toxicair/newtoxics.html